An Internet Protocol (IP) telephony system routes various types of communications, at least in part, via data packets that are communicated over a data network. The data network is commonly the Internet. The types of communications may be, for example, telephone calls, video calls, text and video messages, and other forms of telephony and data communications. The users of the Internet Protocol (IP) telephony system typically gain access to the Internet using an Internet service provider so that they can communicate via the IP telephony system.
Some users or customers of the IP telephony system may engage in communications using telephony devices that are connected by physical lines such as cables or wires to an access point such as an internet port. Such wired telephony devices may, thanks to the services of the IP telephony system, be moved from one physical location to another physical location, but at each such physical location are physically connected in a wired manner to the respective access point.
Other users or customers of the IP telephony system may possess mobile or wireless telephony devices, such as a wireless terminal, user equipment (UE), mobile phone, smart phone, or laptop, tablet, or other device with mobile termination. When such a mobile telephony device is within coverage of an appropriate wireless network (e.g., WiFi or WiMax network) that has connection to the a data network such as the Internet, the communications involving the mobile telephony device may be handled by the IP telephony system in conjunction with the wireless network. In other words, the communications may occur wirelessly between the mobile telephony device and a wireless access point of the wireless network, with the wireless access point in turn being connected to an Internet portal. Access in this manner to the Internet portal enables the mobile telephony device to capitalize upon the service of the IP telephony system in economically routing the communications through the Internet, rather than over existing non-Internet service carriers.
When a mobile telephony device is not in range of a wireless network to gain the benefit of the IP telephony system, the mobile telephony device may instead be served by other carriers and/or services using one or more mobile radio access networks. Such mobile radio access networks typically comprise plural base stations which have both radio frequency transmitting and receiving capabilities to serve macro cells. A macro cell is essentially defined by the extent of the transmitting and receiving capabilities of the base station. The mobile telephony devices located within the cell may communicate with the radio access network through the base station (unless the customer also happens to be within range of another wireless network, such as a WiFi or WiMax wireless network or the like, and exercises the option to use the other wireless network instead of the radio access network). In some instances such a “macro” base station may be called a “radio base station”, “base station”, NodeB, eNodeB, or the like.
Many radio access networks allow a mobile telephony device to roam from cell to cell, either within the same radio access network and radio access technology, or even to roam between cells of differing radio access network and/or radio access technologies. Such roaming between macro cells and technologies of radio access networks typically involves an operation or procedure known as “location update”, or some similar operation.
Consider, for example, a scenario in which a user of a mobile telephony device, having a home carrier in the United States of America, travels to China with the mobile telephony device. When the mobile telephony device is turned on in China, a switch or other element in a Chinese mobile network detects activation of the mobile telephony device. As a result, the Chinese mobile network sends a location update type message to a home location register (HLR) of the American home carrier. The location update message informs the American home carrier that the mobile telephony device is now within service of the Chinese mobile network, so that the American home carrier should transfer all incoming calls directed to the mobile telephony device to the Chinese mobile network. Thereafter, when a new call is placed to the mobile telephony device (now in China), any such new call, regardless of location of origination, is initially directed to the American home carrier. Upon receipt of the new incoming call to the mobile telephony device the American home carrier checks its home location register and thus determines that the mobile telephony device is now serviced by the Chinese mobile network. Accordingly, the American home carrier sends a message to the Chinese mobile network, asking for a registration number (a temporary telephone number assigned by the Chinese mobile network to the mobile telephony device) recognizable by the Chinese mobile network for the mobile telephony device now serviced in China. Upon receiving from the Chinese mobile network the Chinese-provided registration number for the mobile telephony device, the American carrier transfers the incoming call using the Chinese-provided registration number to the Chinese mobile network. In this manner the Chinese mobile network recognizes the transferred incoming call to the mobile telephony device, and can route the transferred incoming call through the Chinese mobile network to the mobile telephony device.
The location update procedure described above applies to roaming mobile telephony devices that are served by non-IP telephony systems. Both IP telephony systems and non-IP telephony systems both provide an additional service known as call forwarding. In a call forwarding service, incoming calls to a customer's nominal directory number are instead routed to an alternate number specified by the customer. Such alternate number may be stored in a home location register or the like maintained by the home carrier network. The call forwarding service may be available both to wired and wirelessly connected telephony devices. Examples of how call forwarding services may be beneficially used by mobile/wireless telephony devices are described in one or more of the following United States patent applications, all of which are incorporated herein by reference: U.S. Pat. No. 8,600,364; U.S. patent application Ser. Nos. 13/492,361; 13/562,542; 13/568,416; 13/597,396; 13/597,916; 13/668,826; 13/671,006; 13/673,043; 13/649,847; 13/671,162; 13/597,485; and 13/669,009.
When call forwarding is to be utilized for a mobile telephony device, the customer or subscriber may input a string of numbers, e.g., a code such as “#21*xxx* (wherein “xxx” is the call forwarding number to be used upon implementation of the call forwarding operation). The input of code a code results in a signal being transmitted to the home carrier that informs the home carrier to start forwarding calls to the number specified in the string (or a number pre-stored with the home carrier) instead of the nominal directory number associated with the wireless telephony device.
In some instances the forwarding number may be a number associated with an IP telephony system, e.g., a server of an IP telephony system. Thereafter, the IP-telephony system may terminate the call over the IP telephony system network to the subscriber when the subscriber is in range of an appropriate internet-connected wireless network, such as Wi-Fi. The call forwarding service is thus implemented at the time of conscious, deliberate activation of the customer/subscriber, and remains in effect until the call forwarding service is removed by a similar conscious, deliberate act of the customer/subscriber. In essence, the call forwarding number remains permanently applied until specifically replaced by the customer/subscriber. Thus, prior art call forwarding services do not effectively cater to the roaming of mobile telephony devices.